The present invention relates to a cleaning tool for the loosening and removal of deposits from the interior wall of tubes.
It is well known that fluid driven projectiles or scrapers can be used for the removal of mud, slim, scale or other deposits from the interior wall of a tube, such as a condenser, heat exchanger or similar tubing. Such scrapers generally comprise one or more cutters or scrapers that extend outwardly from a support. One type of device has a cutter that contains two blades that contact the inside of the tube. Generally, the tail portion of the projectile will contain a section which will enable the projectile to be forced through the tubing by the use of fluid and will also allow for some fluid to pass through the projectile device, cleaning debris from in front of the projectile as the projectile moves through the tube. There are some difficulties with this arrangement, a few of which are the limited contact that a cutter blade has with the inner wall of the tube and the lack of ability to control the pressure exerted by the cutter blades on the inside wall of the tube. Examples of non-adjustable tube cleaning tools are described in U.S. Pat. Nos. 2,170,997, 2,734,208, and 4,281,432.
U.S. Pat. No. 5,305,488 (“488”) shows an adjustable tool that is effective. Because the device shown in 488 is adjustable, its blades have a much greater percentage of contact with the inner wall of the tube, which will allow a greater percentage of deposits to be scraped away and cleaned from the inner wall of the tube for each pass of the projectile through the tube. However, the construction of this tool is relatively complex, and is fabricated from relatively expensive materials. As a consequence, one-piece molded plastic tools have been marketed. These plastic tools are not as effective as the type of tool shown in 488, but they are adequate for certain applications where maximum cleaning is not necessary or desired. A typical one-piece plastic tool is shown in FIGS. 1, 2 and 3. The tool shown in FIGS. 1, 2 and 3 is not, however, adjustable and, consequently, has the shortcomings of other types of tube cleaning tools that are not adjustable.
The present invention is designed to overcome these difficulties by providing an adjustable projectile of simple construction that is less costly than the type of adjustable projectile shown in 488. In instances where a non-adjustable, all-plastic projectile of the type shown in FIGS. 1, 2 and 3 would normally be used, use of the present invention will provide a projectile that will clean the tube more thoroughly on each pass of the projectile through the tube, thereby requiring fewer passes to completely clean the tube, since the force that the cutters of the projectile will exert on the inner surface of the tube is adjustable, which will enable the invention to be used on both hard and soft deposits on the interior wall of the tube, regardless of tube diameter.